Field of the Invention
The present invention relates to a pneumatic tire.
Description of the Related Art
Conventionally, there has been known a pneumatic tire where a plurality of blocks are formed on a tread surface of the pneumatic tire by main grooves extending in the circumferential direction and lateral grooves which intersect with the main grooves, and a recessed portion is formed on an approximately center portion of each block (see JP 05-96913 A, for example).
However, in the pneumatic tire described in JP 05-96913 A, the recessed portions formed in all blocks function as heat radiating holes. That is, compared to an amount of increase of a volume of the tire by making the block large-sized, the increase of an amount of a surface area of the tire is small and hence, there is a possibility that heat generated inside the tire is not properly radiated. The recessed portions are formed only for enlarging such a surface area in view of the above-mentioned possibility.
Although it is expected that the recessed portions exhibit a snow biting effect at the time of traveling on a snow surface, JP 05-96913 A neither discloses nor suggests such a point.